Method of constructing 3d clothing model based on a single image

ABSTRACT

A method of constructing 3D clothing model based on single image, estimating a 3D model of human body of an inputted image and constructing 3D clothing plane according to the clothing silhouette of the inputted image. The method includes utilizing the 3D clothing plane and the 3D model of human body to generate a smooth 3D clothing model through a deformation algorithm. A decomposition algorithm of intrinsic image is utilized along with a shape-from-shading algorithm to acquire a set of detail information of clothing from the inputted image. A weighted Laplace editing algorithm is utilized to shift the acquired detail information of clothing to the smooth 3D clothing model to yield a final 3D clothing model. A 3D clothing model is used to generate the surface geometry details including folds, wrinkles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 14/444,315 filed on Jul. 28, 2014, which claimspriority to Chinese Patent Application No. 201310435284.2, filed Sep.23, 2013. The entire disclosures of U.S. patent application Ser. No.14/444,315 and Chinese Patent Application No. 201310435284.2 are herebyincorporated herein by reference.

TECHNICAL FIELD

The invention relates to the technical fields of computer graphics,computer vision and virtual reality, specifically to a method ofconstructing 3D clothing model based on single image (an inputtedimage).

BACKGROUND OF THE INVENTION

The construction of 3D model of scene object based on image is animportant component of generating virtual reality and virtual scene.Particularly, the construction of 3D model of scene object of non-rigiddeformation such as clothing is the research focus of internationalfrontier at present. 3D clothing model with strong sense of reality isof a value to be widely applied.

The conventional methods to construct clothing 3D clothing model referto the processes of actual processes of designing and cutting a clothingand establish the steps including 2D pattern design, physicalsimulation, etc and utilize the human-involved parameter iterativeoptimization to create a final 3D clothing model. The conventionalmethods of constructing 3D model clothing depend too much on manualoperation and consume a large amount of time in physical simulation.Meanwhile, a higher level of knowledge in clothing field is needed for aperson to perform modeling, so these methods are difficult to getpopular in non-professionals.

The method of constructing 3D clothing model based on sketch allows theuser to design the silhouette and detail information of clothingdirectly on a model of human body. So the 3D clothing is modeled as asurface offset to the model of human body. In particular, theresearchers of the University of British Columbia recently propose amethod of analyzing the sketch of clothing with sensitive content whichcalculates the tension degree between a clothing and human body tosuccessfully improve modeling quality in the loose areas of clothing.However, most of the existing methods of constructing 3D clothing modelbased on sketch have many limitations in human poses and userinteraction. Specifically, on one hand, the existing methods require astanding pose of the model of human body and the skeleton movements arelimited in 2D image plane; on the other hand, the existing methodsrequire the user to design manually silhouette and details of clothing(such as folds and wrinkles, etc) and hence a higher level ofprofessional knowledge is needed for an user.

The technology of 3D clothing acquisition without marker utilizesmultiple synchronized cameras to construct a 3D clothing model through aseries of steps as keeping space-time consistency, re-meshing and 3Ddeformation, etc. The latest technology of acquiring the movement ofhuman body also utilizes several cameras in synchronization and canapproximately model an human body wearing movement clothing. Both of themethods introduced above depend on a professional-level environment ofmulti-view modeling and so can only be used in the laboratories.

The researchers of Max Planck Institute of Germany present a method ofacquiring the surface details of 3D clothing through utilizing theactive lights and a photometric stereo reconstruction algorithm.However, this method is complex in modeling environment which needssetting not only multiple cameras of multi-spectrum and also setting theparticular light sources after calibrated. The researchers of theUniversity of British Columbia utilize a multi-view video of clothingmovement to restore the surface details of 3D clothing through aspace-time deformation method and the clothing edges in video images.This method also needs a multi-view modeling environment and dependspartially some man-machine interaction during the course of designingclothing edge.

In conclusion, the existing methods of constructing 3D clothing modeldepend to a greater degree on setting a multi-view modeling environmentand are difficult to be applied in complex 3D poses of human body anddifficult to automatically acquire the geometry details of clothingsurface.

SUMMARY OF THE INVENTION

In light of the practical demands and the key problems of constructing3D clothing model for the object of human body, the purpose of thepresent invention is to provide a computer with programming to performsteps of a method of constructing 3D clothing model based on singleimage inputted into the computer, the computer needing merely the singleimage to create 3D clothing model with rich surface geometry detailssuch as folds and wrinkles, etc to overcome the shortcomings of theexisting methods in setting multi-view modeling environment, acquiringverisimilar surface geometry details and complex 3D poses of human body,etc.

In order to realize the purpose, the present invention employs atechnical solution as follows:

A method of constructing 3D clothing model based on single image,characterized in that it comprises the steps performed by the computeras follows:

Step 1: To estimate 3D model of human body of and construct 3D clothingplane according to the clothing silhouette of the input image (aninputted image) and display the model of the human body on a computerdisplay which defines an input image.

First, utilize a method of semi-automatic 3D pose estimation method toestimate 3D pose(s) of human body of the input image according to 2Djoint(s) of human body in the input image specified by user viewing themodel of the human body (the input image) on the computer display;estimate the 3D model of human body in the input image through a methodof deformable template according to a human contour line specified inthe input image by user and the estimated 3D pose(s) of human body;specify the clothing silhouette by user in the input image; utilize theestimated 3D model of human body to divide the clothing silhouettespecified by user into silhouette edge and boundary outline.

Then, the computer calculates the projection area of 3D model of humanbody on the image and the skeleton(s) related to clothing area;calculates a directed surface for each skeleton related to the clothingarea through 3D coordinate(s) of skeleton joint(s) and a relativerotation matrix; calculate an intersection line between adjacentdirected surfaces which is used to calculate an internal cutting line ofthe clothing area of the input image; utilize the internal cutting lineto divide the clothing area of the input image into different parts ofwhich each corresponds to one directed surface.

The computer then projects the outline and the internal cutting line ofeach part of the clothing area of the input image on the correspondingdirected surface to form 3D clothing area of each part accordingly onthe computer display; triangulates the 3D clothing area of each part andutilize the apex(s) of the common internal cutting lines betweendifferent 3D clothing areas to form an initial 3D clothing plane whichis also displayed on the computer display.

Finally, duplicate the initial 3D clothing plane; utilize the apex(s) ofthe silhouette edge on the initial 3D clothing plane as the commonapex(s) to combine these initial 3D clothing planes before and afterduplication to form a final 3D clothing plane that is also displayed onthe computer display.

Step 2: To utilize the final 3D clothing plane and the 3D model of humanbody to yield a smooth 3D clothing model through a deformation algorithmand display the smooth 3D clothing model on the computer display.

Firstly, the computer utilizes a Laplace deformation algorithm to deformthe final 3D clothing plane under a set of constraints of outlineapex(s) and the 3D model of human body to initialize a 3D clothingmodel. Then the computer calculates the tension degree of each apex ofthe initial 3D clothing model through calculating the shortest distancebetween the apex(s) of silhouette edge and the surface of the 3D modelof human body. Finally the computer utilizes the rotating surface as thedeformation constraint to initialize again the 3D clothing model in thearea whose tension degree of apex(s) is marked loose to yield a smooth3D clothing model that is displayed on the computer display.

Step 3: The computer utilizes an intrinsic image decomposition algorithmand a shape-from-shading algorithm to acquire the detail information ofclothing from the input image; shift the acquired detail information ofclothing to the smooth 3D clothing mode through the weighted Laplaceediting algorithm to yield a final 3D clothing model that is displayedon the computer display.

Firstly, the computer utilizes the intrinsic image decompositionalgorithm to decompose the input image into a shading diagram and areflectogram; utilize the shading diagram and the shape-from-shadingalgorithm to calculate a relative depth value corresponding to eachpixel point; establish a corresponding relation between the clothingarea of the input image and the final 3D clothing plane, and calculatethe change of the relative depth of each apex of the 3D clothing planeaccording to the depth value corresponding to the pixel point of theclothing area; renew the final 3D clothing plane according to thecalculated change of the relative depth to yield a 3D clothing detailplane.

Then calculate separately the Laplace coordinates of the apex(s) on thefinal 3D clothing plane and the 3D clothing detail plane; utilize thesetwo Laplace coordinates of the apex(s) to calculate the detailinformation of surface geometry of the apex(s) on the 3D clothing.

Then utilize the Laplace coordinates of the apex(s) on the smooth 3Dclothing model and the calculated detail information of surface geometryto calculate the shortest distance between the apex(s) and the apex(s)of silhouette edge so as to build a weighted Laplace deformation energyfunction.

Finally, utilize a linear optimization algorithm to minimize thedeformation energy function mentioned as above to transfer the detailinformation of clothing surface geometry to the smooth 3D clothing modeto yield a final 3D clothing model, which is displayed on the computerdisplay.

Wherein: the “calculate a directed surface of each skeleton” describedin Step 1 is realized specifically through the processes as follows:

Calculate the skeletons related to the clothing area and mark them as{l₁, . . . , l_(i), . . . , l_(n)} and define the directed surface F,for each related skeleton l_(i) as follows:

F_(l) _(i) : L^(l) _(j)Ln_(L)=0.

n_(l) _(i) =R_(l) _(i) [0 0 1]^(T)

Wherein: L^(l) ^(i) _(j) denotes the 3D coordinate(s) of joint(s)related to the skeleton l_(i), L denotes any point on the directedsurface F_(l) _(i) , n_(l) _(i) denotes the normal of the directedsurface F_(l) _(i) , R_(l) _(i) denotes the rotation matrix of theskeleton l_(i) which is 3×3; n_(l) _(i) is determined by the rotationmatrix R_(l) _(i) of the skeleton l_(i) and only the component on Z axisof R_(l) _(i) is concerned for calculation, that is, only the rotationcomponent of the skeleton l_(i) perpendicular to the image plane isconcerned.

Wherein: the “calculate the detail information of surface geometry ofthe apex(s) on the 3D clothing” described in Step 3 is realizedspecifically through the processes as follows:

Calculate the Laplace coordinate(s) corresponding to the apex(s) v_(i)on the 3D clothing plane and denote it as δ_(vi); similarly, calculatethe Laplace coordinate(s) corresponding to the same apex(s) ν_(i) on the3D clothing detail plane and denote it as {tilde over (δ)}_(ν) _(i) ;define ξ_(ν) _(i) as the detail information of the 3D clothing on theapex(s) ν_(i);

ξ_(σ) _(i) =δ_(ν) _(i) −{tilde over (δ)}_(ν) _(i)

Wherein: the “calculate the shortest distance between the apex(s) andthe apex(s) of silhouette edge so as to build a weighted Laplacedeformation energy function” described in Step 3 is realizedspecifically through the processes as follows:

Build a weighted Laplace editing deformation energy function to transferthe detail information of clothing to the smooth 3D clothing model:

$E = {\sum\limits_{i}\; {{L_{v_{i}} - {\overset{\sim}{L}}_{v_{i}} - {w_{i}\xi_{v_{i}}}}}^{2}}$

Wherein: denotes the Laplace coordinate(s) of the apex(s) ν_(i) on thesmooth 3D clothing model, L⁻ _(r), denotes the Laplace coordinate(s) ofthe apex(s) ν_(i) on the 3D clothing after transferred which is anunknown value needing to be solved, ξ_(vi) is the detail information ofsurface geometry of the apex(s) v_(i) on the 3D clothing, w_(i) is thetransferring weight of the apex(s) ν_(i) which will be calculated asfollows:

$w_{i} = ^{- \frac{\mu}{d}}$

Wherein: d denotes the shortest distance between the apex(s) ν_(i) andthe apex(s) of silhouette edge on the smooth 3D clothing model andusually μ=0.5:

Compare with the existing techniques, the beneficial features of thepresent invention are: the method of constructing 3D clothing modelbased on single image according to the present invention takes fulladvantages of 3D model of human body of the input image as well as the3D pose information contained thereof and the shading information of theclothing area of the input image which needs merely single image togenerate 3D clothing model with rich surface geometry details such asfolds and wrinkles, etc so as to overcome the shortcomings of theexisting methods in setting multi-view modeling environment, acquiringgeometry detail of verisimilar surface and complex 3D poses of humanbody, etc.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1(a-g) are the overall schematic diagram showing the method ofconstructing 3D clothing model based on single image according to thepresent invention;

FIG. 2(a) is a schematic diagram showing calculating the internalcutting line(s) of clothing area according to the present invention;

FIG. 2(b) is a schematic diagram showing the result of dividing theclothing area with the internal cutting line(s) according to the presentinvention;

FIG. 2(c) is a schematic diagram showing 3D clothing area according tothe present invention; and

FIG. 3 is a schematic diagram showing a computer that includes a centralprocessing unit (CPU), a display, memory, electronic storage andinputting devices according to the present invention.

EMBODIMENT

Now the drawings are used to describe an embodiment according to thepresent invention in order to better understand the present invention.It is necessary to note in particular that: in the description asfollows, in the case that the main contents of the present invention maybe possibly subject to being weakened if any known function and designis introduced in detail, these descriptions will be omitted here.

As shown schematically in FIG. 3 a computer 10 includes a processor orcentral processing unit (CPU), a display 12, memory 14, electronicstorage 16, such as a hard drive or other data storage device, inputtingdevices such as a scanner 18, a keyboard 20, a digital device 22 (forexample, a mouse or stylus), and an input/output device 24, such as awireless communication device, Internet connection or networkcommunication device. The computer 10 includes a control program thatcontrols the CPU, display 12, memory 14, storage 16 and receives inputfrom the scanner 18, the keyboard 20 and the digital device 22 and sendsand receives data via the output device 24. The computer 10 is alsoreferred to as a controller and can also include other conventionalcomponents such as an input interface circuit and an output interfacecircuit. The memory 14 can include a ROM (Read Only Memory) device and aRAM (Random Access Memory) device. The computer 10 includes graphicsprocessing capability such that digital images can be inputted, analyzedand processed to generate further images and models such that the imagesand generated models, for instance, the images shown in FIGS. 1 and 2,can be displayed individually or all together on the display 12 andstored in the electronic storage device 16. Further, the computer 10 isprogrammed and/or provided with the necessary hardware and software toconduct the steps set forth in the method described herein below. Thekeyboard 20, the digital device 22 (the mouse) and display 12 define auser interface such that a user (not shown) can input data, and interactwith the computer 10 to guide the process and method described hereinbelow. It will be apparent to those skilled in the art from thisdisclosure that the precise structure and algorithms for the computer 10(the controller) can be any combination of hardware and software thatwill carry out the functions of the present invention.

With reference to FIG. 1(a-g), the present invention is illustrated witha series of images generated by the computer 10 that has been providedwith a single scanned inputted image. The single inputted image (FIG.1(a)) can be digitally inputted or can be scanned to produce a digitalimage using the scanner 18. The images generated by the computer 10 arebased on analysis and modeling of the data in the inputted image. Thecomputer 10 utilizes a method of constructing 3D clothing model based onthe single inputted image, the method comprising the steps as follows:

Step 1: To estimate 3D model of human body of and construct 3D clothingplane according to the clothing silhouette of the input image andsubsequently displaying the 3D clothing plane on a display of thecomputer 10.

First, utilize a method of semi-automatic 3D pose estimation method toestimate 3D pose(s) of human body of the input image (as shown in FIG.1(a)) according to 2D joint(s) of human body in the input imagespecified by user; estimate the 3D model of human body in the inputimage (as shown in FIG. 1(b)) through a method of deformable templateaccording to a human contour line specified in the input image by userand the estimated 3D pose(s) of human body. The computer generates the3D pose(s) of human body and 3D model of the human body and stores themin memory and/or in the electronic storage device 16 of the computer 10such they can be displayed on the display 12 of the computer 10.

Then, the user (not shown)using the inputting devices (i.e., thekeyboard 20 and/or the mouse 22) specifies a clothing silhouette in theinput image; utilizes the estimated 3D model of human body to divide theclothing silhouette specified by user into silhouette edge and boundaryoutline. The principle of dividing is: in the case that one outlinespecified by user crosses the project area of the 3D model of human bodyon the image, it will be divided as boundary outline; otherwise, it willbe divided as silhouette edge.

Thirdly, project the estimated 3D model of human body on the image planeto calculate the overlap area between the projection area and theclothing area specified by user; calculate the skeletons related to theclothing area according to the overlap area and the skeleton dividing ofthe 3D model of human body and set them as {l₁, . . . , l_(i), . . . ,l_(n)}.

Fourthly, define the directed surface F_(l) _(i) as follows for eachrelated skeleton l_(i) (as shown in FIG. 2(a), L₁ and L₂ are twodirected surfaces):

F_(l) _(i) : L^(l) ^(i) _(j)Ln_(l) _(i) =0.

n_(l) _(i) =R_(l) _(i) [0 0 1]^(T)

Wherein: L^(l) ^(i) _(j) denotes the 3D coordinate(s) of joint(s)related to the skeleton l_(i) (as shown in FIG. 2(a), l_(i) denotes anypoint on the directed surface F_(l) _(i) , n_(l) _(i) denotes the normalof the directed surface f_(l) _(i) , R_(l) _(i) denotes the rotationmatrix of the skeleton l_(i) which is 3×3; n_(l) _(i) is determined bythe rotation matrix R_(l) _(i) of the skeleton l_(i) and only thecomponent on Z axis of R_(l) _(i) is concerned for calculation, that is,only the rotation component of the skeleton l_(i) perpendicular to theimage plane is concerned

Fifthly, calculate the intersection line between two adjacent surfaces.At the left side of FIGS. 2(a), L₁ and L₂ are two adjacent directedsurfaces in a 3D space and the intersection line between L₁ and L₂ isshown as the dotted line; project the calculated intersection line onthe image plane; utilize the coordinates of the intersection line afterprojection and the corresponding joints on the image to calculate oneinternal cutting line in the clothing area of the input image as shownin the right of FIG. 2(a); all the calculated internal cutting linesdivide the clothing area of the input image into various parts as shownFIG. 2(b) where different colors indicate different part of the clothingarea. It is necessary to note that each constituting part corresponds toone directed surface. It is necessary to note that: during the course ofdividing the constituting parts, it needs to merge the directed surfaceswith same direction as well as their corresponding parts. The deepcolors show the merged parts constituting the clothing area.

Sixthly: project the outlines (including silhouette edge and/or boundaryoutline) and the corresponding internal cutting lines of each partconstituting the clothing area of the input image on the directedsurface corresponding to each part to form the 3D clothing area for eachconstituting part. As shown in FIG. 2(c), the solid line shows theoutline(s) after projection and the dotted line(s) show the internalcutting line(s) after projection.

Seventhly: triangulate the 3D clothing area of each constituting part onthe corresponding directed surface to form multiple triangular meshes ofclothing area; utilize the apex(s) of common internal cutting line(s)among 3D clothing areas to compose a triangular meshing of clothing areawhere two triangular meshing of clothing areas share same apex(s) ofinternal cutting line(s) to form the initial 3D clothing plane.

Finally, duplicate the initial 3D clothing plane; utilize the apex(s) ofthe silhouette edge on the initial 3D clothing plane as the commonapex(s) to combine these initial 3D clothing planes before and afterduplication where both initial 3D clothing planes share same apex(s) ofsilhouette edge to form the final 3D clothing plane M_(u) as shown inFIG. 1(c). Wherein: the initial 3D clothing plane before duplicationforms the front side of clothing and the duplicated initial 3D clothingplane forms the back side of clothing.

Step 2: To utilize the final 3D clothing plane and the 3D model of humanbody to yield a smooth 3D clothing model through a deformationalgorithm.

Firstly, utilize the Laplace deformation algorithm to deform the 3Dclothing plane where the process of deformation is required that (1) theposition(s) of the apex(s) of silhouette edge and the position(s) of theapex(s) of boundary outline will be kept unchanged as much as possible;(2) the position(s) of the apex(s) after deformation will be outside the3D model of human body and will not collide with human body; the initial3D clothing model is generated after deformation.

Then, calculate the shortest distance between the apex(s) of silhouetteedge and the surface of 3D model of human body; build an exponentialdecay function to normalize this distance to be between 0-1 which is setas the tension degree on the apex(s) of silhouette edge where 0 denotesbeing loose and 1 denotes being tight; spread the tension degree of theapex(s) of silhouette edge to all the apex(s) of the initial 3D clothingmodel where the spreading process is required that: (1) the tensiondegrees of adjacent apexes are similar; (2) the spreading has a higherweight along the direction perpendicular to the skeleton and a lowerweight along other directions; after spreading, each apex of the initial3D clothing model will have a value of tension degree.

Finally, renew the initial 3D clothing model in the area(s) of 0 tensiondegree on the apex(s) (that is, these areas marked as being loose)through using the rotation surface, where the process of renewing isrequired that: (1) the positions of the apex(s) of silhouette edge andthe positions of the apex(s) of boundary outline will be kept unchangedas much as possible; (2) the component of the normal vector of the apexon the rotation axis should be maintained as much as possible along therotation direction of the rotation surface; (3) the component of thenormal vector of the apex in the rotation direction should be maintainedas much as possible along the direction of rotation axis of the rotationsurface; (4) the clothing won't collide with the human body; a smooth 3Dclothing model M₁ will be yielded after renewing which is as shown inFIG. 1(d).

Step 3: To utilize the intrinsic image decomposition algorithm and theshape-from-shading algorithm to acquire the detail information ofclothing from the input image; shift the acquired detail information ofclothing to the smooth 3D clothing mode through the weighted Laplaceediting algorithm to yield a final 3D clothing model.

Firstly, utilize the intrinsic image decomposition algorithm todecompose the input image I into a shading diagram S and a reflectogramR where the process of decomposition is required that: I_(p)=S_(p)R_(p)is needed for the pixel point p, wherein: I_(p) denotes the intensityvalue of p on the input image I, S_(p) denotes the intensity value of pon the shading diagram S and R_(p) denotes the intensity value of P onthe reflectogram R.

Then utilize the shading diagram S (as shown in FIG. 1(e)) and theshape-from-shading algorithm to calculate the relative depth value D_(p)corresponding to each pixel point p; establish a corresponding relationbetween the clothing area of the input image and the final 3D clothingplane, and calculate the change of the relative depth of each apex onthe final 3D clothing plane M_(o) according to the relative depth valuecorresponding to the pixel point of the clothing area; renew the final3D clothing plane M_(o) according to the calculated change of therelatiye depth to yield the 3D clothing detail plane {tilde over(M)}_(o) which is as shown in FIG. 1(f).

Then calculate the Laplace coordinate(s) corresponding to the apex(s)ν_(i) on M_(o) and denote it as δ_(ν) _(i) ; similarly, calculate theLaplace coordinate(s) corresponding to the same apex(s) r₁ on {tildeover (M)}_(o) and denote it as {tilde over (δ)}_(ν) _(i) ; define δ_(ν)_(i) as the detail information of the 3D clothing on the apex(s) ν_(i);

ξ_(ν) _(i) =δ_(ν) _(i) −{tilde over (δ)}_(ν) _(i)

Fourthly, build a weighted Laplace editing deformation energy function Eto transfer the detail information ξ_(ν) _(i) of clothing to the smooth3D clothing model M₁;

$E = {\sum\limits_{i}\; {{L_{v_{i}} - {\overset{\sim}{L}}_{v_{i}} - {w_{i}\xi_{v_{i}}}}}^{2}}$

Wherein: L_(ν) _(i) denotes the Laplace coordinate(s) of the apex(s)ν_(i) on M₁, {tilde over (L)}_(ν) _(i) denotes the Laplace coordinate(s)of the apex(s) ν_(i) on the 3D clothing after transferred which is anunknown value needing to be solved, w_(i) is the transferring weight ofthe apex(s) ν_(i) which will be calculated as follows:

$w_{i} = ^{- \frac{\mu}{d}}$

Wherein: d denotes the shortest distance between the apex(s) ν_(i) andthe apex(s) of silhouette edge on M₁ and usually μ=0.5.

Finally, the linear optimization algorithm is used to minimize theenergy function E, that is,

$\underset{\overset{\sim}{V}}{\arg \mspace{11mu} \min}\mspace{11mu} E$

({tilde over (V)} indicates the position(s) of the apex(s) of the 3Dclothing after transferred). Thus, a 3D clothing model {tilde over (M)}₁after transferred is yielded, that is, the final 3D clothing model whichis as shown in FIG. 1(g). Although an explanatory embodiment accordingto the present invention is described above to facilitate theunderstanding of the *sent invention by those skilled in the art, itshould be obvious that the present invention shall not be limited to thescope of the embodiment. For the general technical personnel in the art,as long as any change lies in the spirit and scope of the presentinvention as limited and specified by the claims attached, such changewill be obvious and any invention and creation taking advantage of theconception of the present invention shall be protected hereinaccordingly.

What is claimed is:
 1. A computer system configured to construct a 3Dclothing model based on a single image inputted into a computer havingcomputer graphics, comprising: a computer having a processor, datastorage device, a display, at least one inputting device and at leastone user interface device, the computer being configured to perform thefollowing operations: inputting an image of a person and generating aninputted image corresponding to the image; estimating a 3D model ofhuman body based on the inputted image of the person and constructing a3D clothing plane according to a clothing silhouette corresponding tothe person in the inputted image; displaying the inputted image, the 3Dmodel of human body and the 3D clothing plane on the display; utilizinga method of semi-automatic 3D pose estimation method to estimateestimated 3D pose(s) of human body of the inputted image according to 2Djoint(s) of human body in the inputted image specified by a user via theuser interface device viewing the display; estimating the 3D model ofhuman body in the inputted image through a method of deformable templateaccording to a human contour line specified in the inputted image bythe_user and the estimated 3D pose(s) of human body; specifying theclothing silhouette by user in the inputted image; utilizing the 3Dmodel of human body to divide the clothing silhouette specified by theuser into silhouette edge and boundary outline; calculating a projectionarea of the 3D model of human body on the inputted image and askeleton(s) related to clothing area; calculating a directed surface foreach skeleton related to the clothing area through 3D coordinate(s) ofskeleton joint(s) and a relative rotation matrix; calculating anintersection line between adjacent directed surfaces used to calculatean internal cutting line of the clothing area of the inputted image;utilizing the internal cutting line to divide the clothing area of theinputted image into different parts of which each corresponding to onedirected surface; projecting the outline and the internal cutting lineof each part of the clothing area of the inputted image on thecorresponding directed surface to form 3D clothing area of each partaccordingly and display on the display; triangulating the 3D clothingarea of each part and utilize apex(s) of common ones of the internalcutting lines between different 3D clothing areas to form an initial 3Dclothing plane; duplicating the initial 3D clothing plane; utilizing theapex(s) of the silhouette edge on the initial 3D clothing plane ascommon ones of the apex(s) to combine these initial 3D clothing planesbefore and after duplication to form a final 3D clothing plane;utilizing the final 3D clothing plane and the 3D model of human body toyield a smooth 3D clothing model through a deformation algorithm;utilizing a Laplace deformation algorithm to deform the final 3Dclothing plane under a set of constraints of outline apex(s) and the 3Dmodel of human body to initialize a 3D clothing model; then calculatinga tension degree of each apex of the initial 3D clothing model throughcalculating the shortest distance between the apex(s) of silhouette edgeand the surface of the 3D model of human body; utilizing a rotatingsurface as a deformation constraint to initialize again the 3D clothingmodel in the area whose tension degree of apex(s) is marked loose toyield a smooth 3D clothing model; utilizing an intrinsic imagedecomposition algorithm and a shape-from-shading algorithm to acquiredetail information of clothing from the inputted image; shiftingacquired detail information of clothing to the smooth 3D clothing modethrough a weighted Laplace editing algorithm to yield a final 3Dclothing model; utilizing the intrinsic image decomposition algorithm todecompose the inputted image into a shading diagram and a reflectogram;utilizing the shading diagram and the shape-from-shading algorithm tocalculate a relative depth value corresponding to each pixel point;establishing a corresponding relation between the clothing area of theinputted image and the final 3D clothing plane, and calculating a changeof relative depth of each apex on the final 3D clothing plane accordingto the depth value corresponding to the pixel point of the clothingarea; renewing the final 3D clothing plane according to calculatedchange of relative depth to yield a 3D clothing detail plane;calculating separately Laplace coordinates of the apex(s) on the final3D clothing plane and the 3D clothing detail plane; utilizing these twoLaplace coordinates of the apex(s) to calculate detail information ofsurface geometry of the apex(s) on the 3D clothing; utilizing theLaplace coordinates of the apex(s) on the smooth 3D clothing model andcalculated detail information of surface geometry to calculate theshortest distance between the apex(s) and the apex(s) of silhouette edgeso as to build a weighted Laplace deformation energy function; utilizinga linear optimization algorithm to minimize the weighted Laplacedeformation energy function mentioned as above to transfer the detailinformation of clothing surface geometry to the smooth 3D clothing modeto yield a revised final 3D clothing model; and displaying the final 3Dclothing model on the display and store the final 3D clothing model inthe data storage device.
 2. The computer system according to claim 1,characterized in that: the processor of the computer is configured tocalculate the directed surface of each skeleton as follows: calculatethe skeletons related to the clothing area and mark them as {l₁, . . . ,l_(i), . . . , l_(n)} and define the directed surface F_(l) _(i) foreach related skeleton l_(i) as follows:F_(l) _(i) : L^(l) ^(i) _(j)Ln_(l) _(i) =0.n_(l) _(i) =R_(l) _(i) [0 0 1]^(T) wherein: L^(l) ^(i) _(j) denotes the3D coordinate(s) of joint(s) related to the skeleton l_(i), L denotesany point on the directed surface F_(l) _(i) , n_(l) _(i) denotes thenormal of the directed surface F_(l) _(i) , R_(l) _(i) denotes therotation matrix of the skeleton l_(i) which is 3×3; n_(l) _(i) isdetermined by the rotation matrix R_(l) _(i) of the skeleton l_(i) andonly the component on Z axis of R_(l) _(i) is concerned for calculation,that is, only the rotation component of the skeleton l_(i) perpendicularto the image plane is concerned.
 3. The computer system according toclaim 1, characterized in that: the calculating the detail informationof surface geometry of the apex(s) on the 3D clothing is realizedspecifically by the processor of the computer through the processes asfollows: calculate Laplace coordinate(s) corresponding to the apex(s)ν_(i) on the 3D clothing plane and denote it δ_(ν) _(i) ; as similarly,calculate Laplace coordinate(s) corresponding to the same apex(s) ν_(i)on the 3D clothing detail plane and denote it as {tilde over (δ)}_(ν)_(i) ; define ξ_(ν) _(i) as the detail information of the 3D clothing onthe apex(s) ν_(i);ξ_(σ) _(i) =δ_(ν) _(i) −{tilde over (δ)}_(ν) _(i)
 4. The computer systemaccording to claim 1, characterized in that: the calculating theshortest distance between the apex(s) and the apex(s) of silhouette edgeso as to build the weighted Laplace deformation energy function by theprocessor of the computer is realized through the processes as follows:build a weighted Laplace editing deformation energy function E totransfer the detail information of clothing to the smooth 3D clothingmodel:$E = {\sum\limits_{i}\; {{L_{v_{i}} - {\overset{\sim}{L}}_{v_{i}} - {w_{i}\xi_{v_{i}}}}}^{2}}$wherein: L_(ν) _(i) denotes the Laplace coordinate(s) ν_(i) of theapex(s) ν_(i) on the smooth 3D clothing model, {tilde over (L)}_(ν) _(i)denotes the Laplace coordinate(s) of the apex(s) ν_(i) on the 3Dclothing after transferred which is an unknown value needing to besolved, ξ_(ν) _(i) is the detail information of surface geometry of theapex(s) ν_(i) on the 3D clothing, w_(i) is the transferring weight ofthe apex(s) ν_(i) which will be calculated as follows:$w_{i} = ^{- \frac{\mu}{d}}$ wherein: d denotes the shortest distancebetween the apex(s) ν_(i) and the apex(s) of silhouette edge on thesmooth 3D clothing model and usually μ=0.5.
 5. A method of constructing3D clothing model based on a single image inputted into a computerhaving computer graphics, comprising: inputting an image of a personinto a computer such that a processor of the computer generates aninputted image corresponding to the image of the person; a processor ofthe computer estimating a 3D model of human body based on the inputtedimage of the person and the processor of the computer constructing a 3Dclothing plane according to a clothing silhouette corresponding to theperson in the inputted image; displaying the inputted image, the 3Dmodel of human body and the 3D clothing plane on a display of thecomputer; utilizing a method of semi-automatic 3D pose estimation methodperformed by the processor of the computer to estimate estimated 3Dpose(s) of human body of the inputted image according to 2D joint(s) ofhuman body in the inputted image specified by a user using a userinterface device of the computer, including: estimating the 3D model ofhuman body in the inputted image through a method of deformable templateaccording to a human contour line specified in the inputted image by theuser and the estimated 3D pose(s) of human body; specifying the clothingsilhouette by user in the inputted image; utilizing the 3D model ofhuman body to divide the clothing silhouette specified by the user intosilhouette edge and boundary outline; calculating performed by theprocessor of the computer of a projection area of the 3D model of humanbody on the inputted image and a skeleton(s) related to clothing area,including: calculating a directed surface for each skeleton related tothe clothing area through 3D coordinate(s) of skeleton joint(s) and arelative rotation matrix; calculating an intersection line betweenadjacent directed surfaces used to calculate an internal cutting line ofthe clothing area of the inputted image; utilizing the internal cuttingline to divide the clothing area of the inputted image into differentparts of which each corresponding to one directed surface; projecting,performed by the processor of the computer, the outline and the internalcutting line of each part of the clothing area of the inputted image onthe corresponding directed surface to form 3D clothing area of each partaccordingly; triangulating the 3D clothing area of each part and utilizeapex(s) of common ones of the internal cutting lines between different3D clothing areas to form an initial 3D clothing plane; duplicating theinitial 3D clothing plane; utilizing the apex(s) of the silhouette edgeon the initial 3D clothing plane as common ones of the apex(s) tocombine these initial 3D clothing planes before and after duplication toform a final 3D clothing plane; utilizing the final 3D clothing planeand the 3D model of human body to yield a smooth 3D clothing modelthrough a deformation algorithm performed by the processor of thecomputer; utilizing a Laplace deformation algorithm to deform the final3D clothing plane under a set of constraints of outline apex(s) and the3D model of human body to initialize a 3D clothing model as performed bythe processor of the computer; then calculating a tension degree of eachapex of the initial 3D clothing model through calculating the shortestdistance between the apex(s) of silhouette edge and the surface of the3D model of human body; utilizing rotating surface as a deformationconstraint to initialize again the 3D clothing model in the area whosetension degree of apex(s) is marked loose to yield a smooth 3D clothingmodel; utilizing an intrinsic image decomposition algorithm and ashape-from-shading algorithm performed by the processor of the computerto acquire detail information of clothing from the inputted image;shifting acquired detail information of clothing to the smooth 3Dclothing mode through a weighted Laplace editing algorithm to yield afinal 3D clothing model; utilizing the intrinsic image decompositionalgorithm performed by the processor of the computer to decompose theinputted image into a shading diagram and a reflectogram; utilizing theshading diagram and the shape-from-shading algorithm to calculate arelative depth value corresponding to each pixel point; establishing acorresponding relation between the clothing area of the inputted imageand the final 3D clothing plane, and calculating a change of relativedepth of each apex on the final 3D clothing plane according to the depthvalue corresponding to the pixel point of the clothing area; renewingthe final 3D clothing plane according to calculated change of relativedepth to yield a 3D clothing detail plane; calculating separatelyLaplace coordinates of the apex(s) on the final 3D clothing plane andthe 3D clothing detail plane performed by the processor of the computer;utilizing these two Laplace coordinates of the apex(s) to calculatedetail information of surface geometry of the apex(s) on the 3Dclothing; utilizing the Laplace coordinates of the apex(s) on the smooth3D clothing model and calculated detail information of surface geometryto calculate the shortest distance between the apex(s) and the apex(s)of silhouette edge so as to build a weighted Laplace deformation energyfunction; utilizing a linear optimization algorithm to minimize theweighted Laplace deformation energy function mentioned as above totransfer the detail information of clothing surface geometry to thesmooth 3D clothing mode to yield a revised final 3D clothing model; anddisplaying the final 3D clothing model on the display and store thefinal 3D clothing model in the data storage device.
 6. The methodaccording to claim 5, characterized in that: the calculating of thedirected surface of each skeleton by the processor of the computer isrealized specifically through processes as follows: calculate theskeletons related to the clothing area and mark them as {l₁, . . . ,l_(i), . . . , l_(n)} and define the directed surface F_(l) _(i) foreach related skeleton l_(i) as follows:F_(l) _(i) : L^(l) ^(i) _(j)Ln_(l) _(i) =0.n_(l) _(i) =R_(l) _(i) [0 0 1]^(T) wherein: L^(l) ^(i) _(j) denotes the3D coordinate(s) of joint(s) related to the skeleton l_(i), L denotesany point on the directed surface F_(l) _(i) , n_(l) _(i) denotes thenormal of the directed surface F_(l) _(i) , R_(l) _(i) denotes therotation matrix of the skeleton l_(i) which is 3×3; n_(l) _(i) isdetermined by the rotation matrix R_(l) _(i) of the skeleton l_(i) andonly the component on Z axis of R_(l) _(i) is concerned for calculation,that is, only the rotation component of the skeleton l_(i) perpendicularto the image plane is concerned.
 7. The method according to claim 5,characterized in that: the calculating the detail information of surfacegeometry of the apex(s) on the 3D clothing performed by the processor ofthe computer is realized specifically through the processes as follows:calculate Laplace coordinate(s) corresponding to the apex(s) ν_(i) onthe 3D clothing plane and denote it as δ_(ν) _(i) similarly, calculateLaplace coordinate(s) corresponding to the same apex(s) ν^(i) on the 3Dclothing detail plane and denote it as {tilde over (δ)}_(ν) _(i) ;define ξ_(ν) _(i) as the detail information of the 3D clothing on theapex(s) ν_(i);ξ_(σ) _(i) =δ_(ν) _(i) −{tilde over (δ)}_(ν) _(i)
 8. The methodaccording to claim 5, characterized in that: the calculating theshortest distance between the apex(s) and the apex(s) of silhouette edgeperformed by the processor of the computer so as to build the weightedLaplace deformation energy function is realized specifically through theprocesses as follows: build a weighted Laplace editing deformationenergy function E to transfer the detail information of clothing to thesmooth 3D clothing model:$E = {\sum\limits_{i}\; {{L_{v_{i}} - {\overset{\sim}{L}}_{v_{i}} - {w_{i}\xi_{v_{i}}}}}^{2}}$wherein: L_(ν) _(i) denotes the Laplace coordinate(s) of the apex(s)ν_(i) on the smooth 3D clothing model, {tilde over (L)}_(ν) _(i) denotesthe Laplace coordinate(s) of the apex(s) ν_(i) on the 3D clothing aftertransferred which is an unknown value needing to be solved, ξ_(ν) _(i)is the detail information of surface geometry of the apex(s) ν_(i) onthe 3D clothing, w_(i) is the transferring weight of the apex(s) ν_(i)which will be calculated as follows: $w_{i} = ^{- \frac{\mu}{d}}$wherein: d denotes the shortest distance between the apex(s) ν_(i) andthe apex(s) of silhouette edge on the smooth 3D clothing model andusually μ=0.3.